As you age, there's no doubt that staying in shape and getting regular exercise can be extremely beneficial. According to the U.S. Department of Health and Human Services, all adults should be getting at least 150 minutes of moderate physical activity each week. On top of that, the department recommends strength training two times a week, which could include resistance or weight training. This is especially important for women over 40 -- who are at increased risk of osteoporosis -- since resistance training can help strengthen bones. While there are many ways to incorporate a weight training routine into your fitness schedule, you can work most major muscles with just a simple set of dumbbells.

Step 1

Warm up for 5-10 minutes. According to the Centers for Disease Control and Prevention, a short walk or other light exercise before strength training brings blood flow to the muscles and prepares your body for what it's going to be doing.

Step 2

Work the arms by beginning with a dumbbell with a low weight, such as 1, 3 or 5-pound weight. Sitting at the edge of a chair with your feet about shoulder-width apart, pull the dumbbell from a position near your knees, upward toward your chest. Slowly lower the dumbbells back toward your knees. As with all exercises mentioned here, start with a single set of 12 repetitions.

Step 3

Perform the overhead arm press to work the shoulders and arms. From your position in the chair, hold one dumbbell in each hand and slowly press upward until your arms are almost completely straight overhead. As with every weight-lifting motion, be sure to lower the dumbbells slowly and deliberately back to their starting position.

Step 4

Perform the chest press to work the muscles of the chest and shoulders. Lie flat on your back on the floor or on a weight bench, holding a barbell in each hand in a perpendicular position from the body, near the shoulders. Push the barbells upward until your arms are almost straight, and then slowly lower them back to the starting position.

Step 5

Work the muscles of your calves by standing with your feet about shoulder-width apart, with a dumbbell in each hand. Raise yourself up onto your toes, and then lower yourself back down slowly. You should feel a burn in the muscles at the back of your legs.

Step 6

Work the major muscles of the legs -- as well as the core and arm muscles -- by performing lunges while holding dumbbells. Stand with your feet about shoulder-width apart, with the dumbbells at your sides. Step forward with one foot, lowering the other knee to the ground. As you move, swing the dumbbells toward your chest, in a motion similar to the biceps curl.

Step 7

Cool down by stretching the major muscles of your body. Hold the back of a chair and grab the front of one of your toes to stretch the quadriceps, and then touch your toes or simply "hang" to stretch the calves and hamstrings. Clasp your hands behind your back to stretch the shoulders and arms, and then clasp your hands in front of your body to stretch the shoulders and neck.

Step 8

Get adequate nourishment and rest. According to BodyBuilding.com, muscles go through a process called "hyperplasia" after lifting. One theory is that lifting weights breaks down muscles, and then the body responds by trying to compensate, building bigger muscle tissues. What this means to you: you'll need to give yourself at least one day of rest in between weight training workouts. Also be sure you're properly nourished; according to a study published in the Journal of Aging and Physical Activity, older adults doing strength training should be getting about 1 gram of protein per kilogram of body weight, per day.

Tip

Increase the number of sets for each weight training exercise, gradually working your way up to heavier weight and more repetitions. This will help you gradually build strength and avoid hitting a plateau in your training. If you need help staying motivated, talk with a trainer or work with a friend to set fitness goals, and then reward yourself when you meet those goals.

Many gyms also have weight machines that allow you to do weight-training exercises without the need for your own equipment. If you've never used them before, hire a trainer or talk to your gym staff for a tutorial.

About the Author

Nicole Vulcan has been a journalist since 1997, covering parenting and fitness for The Oregonian, careers for CareerAddict, and travel, gardening and fitness for Black Hills Woman and other publications. Vulcan holds a Bachelor of Arts in English and journalism from the University of Minnesota. She's also a lifelong athlete and is pursuing certification as a personal trainer.